You can register up to a combination of sixteen numbers to your Calling Circle, including:
Up to 11 UK mobile numbers / UK landline nubmers (10% discount)
Up to 6 international numbers (10% discount)
One 0845 number (33% discount)
One of your Calling Circle numers can be a primary number and you can receive an additional 10% discount on top of the standard Calling Circle discount.

Potential Charges from BT Engineer Visit

Should you require or request a BT engineer visit it is important for you to be aware of potential charges. Until an engineer has been to your premises and can confirm the cause of the fault we are unable to confirm whether or not you will be charged.
As a guideline, if the fault is found to be with a piece of equipment connected to your phone line, for example your telephone handset or if it is something that you have caused or could have prevented within the boundaries of your premises (your home or garden), or if there is an upgrade required to your line to get an acceptable level of Broadband service, you will be charged for an engineer visit. If the engineer is unable to gain access to your premises, replicate your fault or cannot find a fault then you will also be charged.

How do I add or change calling features and Boosts?

You can add or change calling features online in My Account. To add or change calling features, take the following steps:
Go to manage services in My Account and sign in.
You can manage your landline features from this area.
You can also learn more about which calling features you can add to your service.